Abstraсt: Heavy water and deuterium are used in various fields of science and technology. After the collapse of the USSR, there was no heavy water production in Russia. In 1995 a pilot plant for hydrogen isotopes separation by the method of combined electrolysis and catalytic exchange has been created at PNPI and in operation for a long time. The plant is used for development of hydrogen isotopes separation process and for reprocessing heavy water waste. The plant puts out heavy water and deuterium gas, including heavy water purified from tritium. The plant’s capacity meets the current needs of Russian enterprises and organizations in the heavy water and deuterium.
Keywords: heavy water, deuterium, tritium, heavy water production plant, combined electrolysis and catalytic exchange.
Abstraсt: The effect of the addition of biologically active substance to a the polymer solutions on its rheological properties, and electrical conductivity has been studied. The rheological properties of hyaluronic acid solutions and hyaluronic acid solutions with the addition of curcumin were investigated. The electrical conductivity of polymers solutions was measured.
Keywords: hyaluronic acid, curcumin, dimethyl sulfoxide, viscosity, electrical conductivity.
Abstraсt: Fe, Ni-containing mono-and bimetallic catalysts based on y-Al2O3 were synthesized, characterized by scanning electron microscopy with energy dispersive elemental analysis (SEM / EDA), X-ray diffractometry (XRD), electron magnetic resonance (EMR) and tested in the methanation of carbon dioxide. The influence of the conditions of preliminary heat treatment on the distribution of iron and nickel in the catalyst structure, phase composition, magnetic and catalytic properties of the synthesized systems has been established. According to XRD data, the size of the coherent scattering region (CSR) of crystalline phases in the samples under study (in oxidized and reduced ones) does not exceed 30 nm. It is assumed that the micron-sized particles observed in the SEM images are composed of nanosized grains and the average particle size of y- Al2O3 and nickel, estimated from the diffraction patterns, are ~ 30 and 18 nm, respectively. It is shown that the EMR spectra are characteristic to samples having a superpara / ferrimagnetic nature and the conditions of heat treatment of the samples noticeably affect their shape, intensity, width, and values of magnetic resonance parameters. It is shown that under the conditions of CO2 methanation (300-400°С) the catalyst is poorly crystallized y- Al2O3 containing nano-sized particles of magnetite and nickel. A scheme for the methanation of CO2 with the participation of these particles is given.
Keywords: carbon dioxide, hydrogenation, methane, fe, ni/ai oxide catalysts, superpara/ferromagnetic particles.
Abstraсt: The main stages of the synthesis of bis (ethanediol-1,2) molybdate using ammonium paramolybdate and monoethylene glycol are shown. A high solubility of ammonium paramolybdate in glycol was found. The state of the obtained compound in glycol solutions and the effect of the solvent composition on the pH value were studied. The composition of the dissolved molybdenum compound has been established by the methods of electronic and IR spectroscopy.
Keywords: ammonium paramolybdate, monoethylene glycol, synthesis, bis (ethanediol-1, 2) molybdate, epoxidation catalyst, olefins.
Abstraсt: Bitumen grade BND 60/90 was modified with additives based on secondary raw materials from polyethylene and petroleum resin. The resulting compositions were used to modify asphalt mixtures. The use of modified bitumen makes it possible to increase the durability of asphalt concrete and its strength at extreme temperatures.
Keywords: bitumen, modifiers, polyethylene, petroleum resin, tensile strength.
Abstraсt: The regularities of the process of synthesis of low-base anionites intended for water purification from acrylic acid nitrile with the addition of methyl methacrylate were investigated. The influence of the conditions of the copolymerization reaction of acryloni-trile and divinylbenzene, as well as the properties of the dispersion medium and the composition of the polymerization mixture on the quality of the intermediate copolymer and the final anionite was shown. The optimal parameters of anionite synthesis, at which polymer sorbents with high capacitance and strength characteristics corresponding to the best foreign samples are obtained, were determined.
Keywords: ion exchange resins, low-base anionites, polymer sorbent technology.
Abstraсt: This work is devoted to the depolymerization of polycarbonate waste in ethylene glycol at atmospheric pressure at 180°C. Based on the screening of various catalysts, it was found that ZnCI2 is the most effective one. Based on GC and GC-MS analyzes, it was determined that during the process, in addition to the main decomposition of polycarbonate to bisphenol A and ethylene carbonate, there are several side reactions of intermolecular dehydration of polyols. In addition, it was found that the presented recycling method is insensitive to the presence in the reaction mixture of impurities – plasticizers that are part of the plastics.
Keywords: polycarbonate, waste, depolymerization, glycolysis, catalyst, ecology.
Abstraсt: The article deals with the issues of selective extraction of hardness salts from highly mineralized waters. A hybrid softening technology is proposed? Is’s combines the processes of reagent softening and membrane separation. To analyze the effectiveness of the proposed technology, the indicators of the optical density of solutions, titrimetric determination of hardness cations, and the productivity of the installation were used.
Keywords: water softening, hardness salts, water treatment, membrane separation.
